UV Laser Marking on Electronic Components

The experiment was designed to compare the effectiveness of UV laser marking on microelectronic components, and to explore its precision, efficiency and stability.The company has combined industry needs with analysis of the differences between UV lasers and traditional marking methods, providing engineers and manufacturers with useful references to solve the core problems of difficult-to-recognize small characters and wear resistance.

Why are electronic components getting smaller and smaller?

Now that electronic devices are getting lighter and thinner, the size of the components is shrinking too.What used to be a sesame-sized area now can be the size of a pinhead.This makes traditional ink printing or laser printing useless. Either the printing will be blurred and illegible or the printing will wear off in a few days.The production line is often plagued by customer complaints: "We can't read the model number on this batch of components!

What is it about UV lasers that makes them so strong?

We tested the three main types of laser marking equipment on the market: fiber laser, CO2 laser and ultraviolet laser.The results showed that in a 0.3 mm x 0.3 mm identification area, the number of possible combinations is 1018.

The accuracy of the two methods can be compared.

The ultra-violet laser can engrave characters with a line width of 5 microns, three times finer than with the fiber laser.Take, for example, the character "A7" with its diagonal slash. Using UV equipment, the edges are as sharp as a knife cut, while the other two methods produce a ragged edge.

The results of the adhesion tests are as follows:

After being rubbed with an alcohol-soaked cotton swab 50 times, the UV-printed characters are only slightly faded, while the ink-printed characters are already smeared beyond recognition.This is because ultraviolet laser light directly changes the molecular structure of the surface layer, rather than just "drawing" on the surface.

Speed and cost.

Although the UV equipment costs about 20 % more per unit, it has the advantage of not requiring consumables.If we assume that we mark 20,000 parts a day, then in three months we can recoup the difference in price.But I must remind everyone that the results vary greatly depending on the material. The results of ceramic substrates are one level lower than for metal.

A guide to avoiding pitfalls.

Higher parameters are not necessarily better.

When we first started testing, we turned the power up to the maximum, and ended up burning small pits in the plastic casing.Later, it was discovered that for ABS plastic parts, a 35 % power setting with high frequency pulses produced even sharper pictures.

The influence of the surrounding light is greater than you might imagine.

The common warm light fluorescent lamps found in factories reduce the contrast of UV markings by about 15 %.They suggest adding a light shield to the marking area, or changing the lighting to use neutral light, which would increase the success rate of the inspection camera.

Don't be lazy about regular maintenance.

The mirrors in UV lasers are especially prone to dust accumulation, and we've had our share of problems. One time, after a two-week period without cleaning, the engraving depth dropped from 30 microns to 10 microns.Now the mirrors are dusted with a special cloth saturated in alcohol every Wednesday, and stability is much improved.

How can they be further improved?

Recently I tried spraying a nanocoating onto the surface before marking, and contrast increased by 40 % immediately.But the cost of this technology is currently too high, so we only recommend it for military products.Some of our colleagues are trying automatic focusing systems, which apparently work well on curved surfaces.